Antibody Response to Sars- Cov -2 Mrna Vaccine in Kidney Transplant Recipients

Purpose: Kidney transplant recipients are vulnerable to develop severe form of COVID19 Infection. Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine has significantly improved incidence of COVID19, seroconversion rates in immunosuppressed patients post vaccine is variable and unpredictable. We aim to evaluate the rates of antibody response to SARS-CoV-2 mRNA vaccine and identify factors affecting immunogenicity among kidney transplant recipients Methods: We retrospectively reviewed 327 kidney transplant recipients who received 2 doses of mRNA Vaccine and did not develop COVID19 prior to antibody testing. SARS- CoV- 2 antibody response and risk factors associated with negative serology were evaluated after 2 doses of mRNA vaccine. Patients who tested positive were divided into four quartiles based on titers and analyzed using ANOVA. Result(s): 250 (76.5%) recipients had positive titers and 77 (24%) did not. Poor response was associated with older age (p=0.06) and male gender(p=0.03). Race, immunosuppression regimen and trough levels were not significant. Analysis of recipients who developed antibody revealed age, time from transplant, history of diabetes and steroid as factors affecting titer level (Table 1). Conclusion(s): Understanding immunologic response to SARS-CoV-2 vaccine in kidney transplant recipient is important to prevent life threatening infection. Identification of transplant recipients at risk of low vaccine response can be a guide to formulate personalized therapy.

Risk factors of covid-19 in kidney transplant recipients

Purpose: Kidney transplant recipients have been shown to develop a severe form of coronavirus disease (COVID-19) that poses a significant mortality risk. The aim of this study was to evaluate risk factors associated with acquiring COVID-19 in our kidney transplant population. Methods: We retrospectively reviewed the medical records of all kidney transplant recipients in our national transplant registry. There were 249 out of 693 kidney transplant recipients who underwent SARS-CoV-2 infection testing by August 1st, 2020. All testing was done by government using RT-PCR of throat and nasal swabs. Forty-three of the tested patients had positive COVID-19 (17%), while the remaining 206 were negative. Mann-Whitney and Fisher's exact tests were used to study the different continuous and categorical variables, respectively. Results: Among patients tested for COVID-19, Asian ethnicity (37% vs. 16%, P=0.003), history of hypertensive nephropathy (23% vs. 9%, P=0.01) and deep vein thrombosis (12% vs.1%, P=0.002) were statistically significant in COVID-19 positive group compared to COVID-19 negative group. Tacrolimus trough level at the time of COVID-19 testing was also significantly higher in COVID-19 positive patients (7.7 ng/mL vs. 6.6 ng/mL, P=0.03). Recipient age, gender, year of transplant, donor type, maintenance immunosuppression, flu vaccine within 1 year and use of ACE inhibitors or ARBs were all similar in both groups. Most patients with positive COVID-19 were symptomatic at the time of testing compared to negative patients (84% vs. 18%, P=0.0001). However, close contact with positive COVID-19 people was similar in both groups (14% vs. 14%, P=1). Conclusions: Prevention and reduction of COVID-19 infection development is crucial in kidney transplant recipients to avoid unfavorable outcomes. With the widespread of COVID-19 worldwide, avoiding exposure might not be possible. Our results suggest that targeting lower tacrolimus trough levels may reduce the risk of acquiring SARS-CoV-2 infection.

Risk factors associated with severe covid19 illness in kidney transplant recipients

Purpose: COVID19 is an acute respiratory infection that is caused by the SARSCOV-2 that has been shown to be highly contagious and poses a significant mortality risk. Kidney transplant recipients are shown to be at increased risk of acquiring and developing a severe form of the disease compared to the general population. There is limited evidence to guide the transplant community on methods to reduce disease severity. We aim to evaluate risk factors associated with severe [requiring hospitalization] or critical [requiring ICU care] COVID-19 illness in kidney transplant recipients. Methods: We evaluated kidney transplant recipients with COVID19 between February to August 2020. Among 748 recipients followed at our center, 43 recipients (5.7%) were diagnosed with COVID19 infection through nasopharyngeal swab PCR. Of those, 9 patients were treated within an isolation facility, 25 patients admitted to the hospital and 9 patients were admitted to the intensive care unit (ICU). We evaluated demographic, clinical and laboratory factors to evaluate severity of illness by using Kruskal-Wallis for continuous variables and chi square test for categorical. Results: Older age was associated with ICU admission (57 vs. 53 vs. 45 P=0.03) while gender, ethnicity and type of transplant were similar between the three groups (Table 1). In addition, CNI level, MMF dose or base line creatinine was not significantly different between the three groups. Presentation with fever, shortness of breath and hypoxia were more frequent in ICU group. Laboratory findings of lymphopenia, low Albumin, high CRP and high procalcitonin at presentation were also more frequent in ICU group. Treatment with hydroxychloroquine, Oseltamivir, Ritonavir, Azithromycin, and reduction of immunosuppression were more frequent in ICU (table 2). We observed 14 patients with graft dysfunction and majority were in ICU group. Furthermore, in the ICU group, 3 recipients required renal replacement therapy and of those there was a single death. Conclusions: Severity of COVID19 infection is variable among our transplant population. Prognostication of COVID19 severity in kidney transplant recipient is crucial for early recognition of critical illness and may offer the benefit of early therapy such as antiviral or immunosuppression reduction in this high-risk group.

Sustained low-efficiency dialysis vs. Continuous renal replacement therapy in critically ill COVID-19 Patients

Background: Acute kidney injury among patients with COVID-19 infection is a poor prognostic indicator. There is limited evidence to guide the nephrology community if there are any risk or advantages of using sustained low-efficiency dialysis (SLED) or continuous renal replacement therapy (CRRT). We aim to evaluate the clinical outcomes of COVID-19 patients receiving renal replacement therapy in the intensive care unit (ICU). Methods: This is a retrospective chart review of adult patients with COVID-19 admitted to ICU in the state of Qatar who had 1)acute kidney injury and 2)received renal replacement therapy between February to August of 2020. We evaluated clinical characteristic, severity of illness, mortality, and renal outcomes at 30 days. Results: Among 127 patients with acute kidney injury requiring dialysis in ICU, 16 patients were on CRRT, 68 patients were on SLED, and 43 patients were on combination. We did not observe significant difference among age, gender, ethnicity or baseline creatinine. Most common indication for indication of dialysis was volume overload followed by acidosis in all three groups with serum creatinine of 264umol/L vs 499umol/L vs 351umol/L in CRRT, SLED and CRRT+SLED, respectively. Inflammatory markers, Pressore requirement and APACHE II score were similar between all groups. 30-day Survival was 23%, 50% and 9%. Among 34 patients on SLED who survived, 6 were dialysis dependent post COVID-19 infection. Conclusions: Acute kidney failure in critically ill COVID-19 patients is associated with high mortality. A lower mortality, but high morbidity is observed in patients receiving SLED in critical care setting. Further investigation of SLED in COVID-19 should be considered.